JP 2005-138964A discloses an image forming apparatus capable of printing on the front surface and the opposite surface of a sheet. The image forming apparatus includes a process unit, a fixer, reverse rollers, and a sensor. The process unit forms a developing agent image onto the sheet. The fixer includes a heating section and pressure rollers to, while transferring the sheet, fix the developing agent image, formed at the process unit, to the sheet. The reverse rollers convey the sheet transferred from the fixer. The sensor is disposed between the fixer and the reverse rollers to detect the sheet. When the image forming apparatus performs duplex printing, the reverse rollers first rotate positively to convey the sheet transferred from the fixer. The reverse rollers then rotate oppositely after elapsing a predetermined period of time since the sensor detects the trailing end of the sheet. This causes the sheet to be conveyed in a direction opposite to the direction in which the sheet is to be discharged, and causes the sheet to return to the process unit.
In the image forming apparatus, a branching member is disposed between the fixer and the reverse rollers. The branching member guides the sheet to a passage toward the process unit when the sheet is conveyed by the reverse rollers rotating oppositely. The sensor is disposed between the branching member and the reverse rollers.